This invention relates to containers or capsules for receiving, storing, shipping and mixing ingredients which must be kept separate until needed for use.
The invention is particularly useful in the making of dental amalgams by mixing mercury and silver alloy powders. These ingredients require careful measurement and mixing and they must be kept separate until just before use.
Because of the need for delicate measuring apparatus and the time consuming operation of measuring and mixing by dentists, the art has developed a number of capsule constructions. In them the mercury and the silver powders, in bulk or tablet form were kept in separate compartments until just before the amalgam was to be prepared and used. These prior constructions required three or more parts, including two container bodies and a screen, or a valve, which required rotation or sliding of the container parts until the valve ports came into register.
One of the problems in the prior art was keeping the mercury from leaking during the mixing and trituration of the ingredients. This led some workers to use three container parts, thus adding to the cost of manufacture due to the need for three dies or molds and more molding material.
It is an object of this invention to provide a capsule or container having only two cooperating parts which when held tightly together hermetically seal two ingredients in two separate cavities and which when loosened and inverted permit direct flow of one ingredient into a chamber for mixing with the other ingredient.
Other objects and advantages will appear as the invention is described in connection with the drawing.
According to the invention, a container consisting of two parts which are connected by a screw threaded connection and each container part has a cylindrical cavity, which together provide a chamber wherein two ingredients are mixed. One container part has an annular cavity in which one ingredient is contained while a second ingredient is contained in the aforementioned cavity of that part. Sealing means preferably in the form of concentric annular ribs are provided on the edges of the cavities engage with shoulder means on the other container part so that when the parts are screwed tight the ingredients are maintained separately and out of contact with one another but when the sealing engagement of the ribs and shoulder means is loosened and the container is inverted, the two ingredients can flow together in the mixing chamber and mixed by shaking the container. The connection of the two container parts is tightend before the shaking.
In accordance with the present invention, there is provided a container for storing and mixing ingredients consisting of a first part having an inner, first wall and an outer, second wall. The first wall has a circumferential first wall edge on which first annular sealing means are formed, the first wall defining an inner cavity open at one end and adapted to hold a first ingredient. The second wall has a second wall edge on which second annular sealing means are formed, the second wall being disposed circumferentially outwardly of the first wall and joined thereto to define an annular cavity disposed outwardly of the first wall edge and open at one end. The annular cavity is adapted to hold a second ingredient, the open ends of the first and annular cavities facing the same direction and the second sealing means are disposed concentrically outwardly of the first sealing means. A second part having a second part wall defining a second cavity open at one end is also provided, the second part further having an annular shoulder means formed thereon. Respective cooperating interengageable means are formed, respectively, on the first and second parts and are adapted to cooperate with each other to engage the first and second parts with each other whereby the first and second cavities cooperate to form a mixing chamber and the first and second sealing means firmly engage the annular shoulder means to seal the annular cavity and the mixing chamber both from each other and from exteriorly of the container. The interengageable means are releasable by relative rotational movement of the first and second parts to a selected extent whereby the first and second parts are axially moved relative to each other to separate the first sealing means from the annular shoulder means sufficiently to provide a flow path over the entire periphery of the shoulder means from the annular cavity to the mixing chamber while maintaining both sealed from exteriorly of the container, so that upon inverting of the container the second ingredient in the annular cavity may flow into said mixing chamber for mixing of said ingredients.
In accordance with one aspect of the invention, the container further includes an inclined portion on the second container part adjacent the annular shoulder means and positioned and configured to sealingly engage the first wall adjacent the first wall edge when the first and second parts are engaged by the interengageable means to provide a second inner seal which cooperates with the first sealing means to provide a double seal between the mixing chamber and the annular cavity.
In accordance with another aspect of the invention, the container further includes a circumferentially extending surface on the first part adjacent the second wall edge thereof, this circumferentially extending surface being positioned and configured to sealingly engage the second part when the first and second parts are engaged by the interengageable means to provide a second outer seal which cooperates with the second sealing means to provide a double seal between the annular cavity and exteriorly of said container.
Certain other aspects of the invention provide the interengageable means in the form of mating interior and exterior screw threads and the sealing means in the form of ribs, preferably in the form of ribs formed with substantially straight converging sides meeting at approximately a 90.degree. angle.